Blood washing and separation system

ABSTRACT

A blood washing system ( 20 ) having a rotor ( 22 ) defining an internal chamber for receiving a multi-component fluid and a skimmer assembly ( 24 ) including a moveable buoy ( 28 ) having an orifice ( 32 ) fluidly connected to an access port for the rotor for selectively withdrawing separated fractions of the multi-component fluid. The multi-component fluid can be fed into the internal chamber before the rotor ( 22 ) can be rotated at a first speed to fractionate the multi-component fluid. A brake can be applied to the rotor to slow rotation of the rotor to a slower second speed or stop rotation of the rotor causing the solid and denser fluid fractions to settle on the bottom wall ( 44 ) of the rotor ( 22 ). The buoy ( 28 ) can have a specific gravity corresponding to a selected fraction such that the buoy floats on a surface of the selected fraction, wherein the fractions floating on the selected fraction can be withdrawn through the orifice ( 32 ).

CLAIM OF PRIORITY

This application claims the benefit of U.S. Provisional PatentApplication Ser. No. 62/508,820, filed on May 19, 2017, the benefit ofpriority of which is claimed hereby, and which is incorporated byreference herein in its entirety.

TECHNICAL FIELD

This document pertains generally, but not by way of limitation, toseparation systems and related methods for separating of components of amultiple component material.

BACKGROUND

Whole blood samples are often fractionated to separate red blood cells,platelets, and other cellular materials from the plasma and other fluidcomponents of the whole blood. A selected fraction, typically red bloodcells or cellular materials, can be selectively withdrawn from thefractionated whole blood sample for use in certain medical applications.The isolated cellular material is often further processed by adding oneor more wash fluids to the isolated cellular materials to remove anyplasma or other undesirable fluids or materials clinging to orintermixed with the desired cellular material. The resulting washsolution comprising cellular material within the wash fluids is oftenfractionated again to separate and isolate the cellular material fromthe wash fluids.

For certain medical applications, the cellular materials must often bewashed multiple times to cleanse the cellular material to certainpredetermined standards. However, each wash cycle requires the additionof new wash fluids, fractionation of the wash solution, and isolation ofthe cellular materials from the wash fluids, which is time-consuming andis often labor intensive. Also, as the wash solution is typicallycentrifuged to fractionate the wash solution, separate containers mustbe connected to add or withdraw wash solution from the centrifuge rotorbefore being disconnected to permit rotation of the centrifuge rotor forfractionation. The repeated connection and disconnection of separatecontainers can increase the risk of contamination or degradation ofcellular material within the centrifuge rotor.

OVERVIEW

The present inventors have recognized, among other things, that aproblem to be solved can include efficiently washing cellular materialwithout excessive risk of contamination or degradation of the cellularmaterial. In an example, the present subject matter can provide asolution to this problem, such as by providing a rotor defining aninternal chamber for receiving a multi-component fluid and a skimmerassembly including a moveable buoy. The moveable buoy can have anorifice fluidly connected to an access port for the rotor forselectively withdrawing separated fractions of the multi-componentfluid. The multi-component fluid can be fed into the internal chamberbefore the rotor can be rotated at a first speed to fractionate themulti-component fluid. A brake can be applied to the rotor to slowrotation of the rotor to a slower second speed or stop rotation of therotor, which can cause the solid fractions and denser fluid fractions tosettle on the bottom wall of the rotor.

The buoy can have a specific gravity corresponding to a selectedfraction such that the buoy floats on a surface of the selectedfraction, wherein the orifice is oriented such that the fractionsfloating on the selected fraction can be withdrawn through the orifice.Additional fluids (e.g. wash fluids, diluents) can be added to theisolated fractions within the internal chamber through the orifice ofthe buoy prior to rotation of the rotor at the first speed forfractionation. The contaminated wash fluids can be fractionated from themixture and withdrawn such that the “washed” selected fraction remains.After the targeted fractions have been sufficiently washed, the selectedfraction can be entrained within a wash fluid or other fluid beforebeing withdrawn from the internal chamber through the orifice of thebuoy.

This overview is intended to provide an overview of subject matter ofthe present patent application. It is not intended to provide anexclusive or exhaustive explanation of the present subject matter. Thedetailed description is included to provide further information aboutthe present patent application.

BRIEF DESCRIPTION OF THE DRAWINGS

In the drawings, which are not necessarily drawn to scale, like numeralsmay describe similar components in different views. Like numerals havingdifferent letter suffixes may represent different instances of similarcomponents.

The drawings illustrate generally, by way of example, but not by way oflimitation, various embodiments discussed in the present document.

FIG. 1 is a schematic, partial cross-sectional top perspective view ofthe blood washing system according to an example of the presentdisclosure.

FIG. 2 is a cross-sectional side view of a blood washing system havingfloats floating on a surface of a supernatant according to an example ofthe present disclosure.

FIG. 3 is a cross-sectional side view of the blood washing systemdepicted in FIG. 2, wherein the floats move to track the surface of thesupernatant as the supernatant is withdrawn.

DETAILED DESCRIPTION

As depicted in FIG. 1, a blood washing system 20 for washing cellularmaterial, according to an example, can include a rotor 22 forfractionating a multi-component fluid and a skimmer assembly 24 forwithdrawing a selected fraction of the multi-component fluid from therotor 22. The rotor 22 can define an internal chamber 26 for receiving amulti-component fluid, such as a whole blood sample, a wash solutioncomprising cellular material suspended in a wash fluid, or othermulti-component fluids containing solid material suspended in a fluid.The rotor 22 can be rotated about a rotational axis x-x to fractionatethe multi-component fluid into a plurality of fractions. The pluralityof fractions can comprise at least one solid fraction containing thesolid material (e.g. red blood cells) and at least one liquid fractioncontaining the liquid material (e.g. plasma). In certain examples, theplurality of fractions can comprise multiple liquid fractions eachhaving a different density. The skimmer assembly 24 can include a buoy28 moveable along a buoy track 30 within the internal chamber 26. Thebuoy 28 can float on a surface of a selected fraction or a boundarybetween adjacent fractions. The buoy 28 can define an orifice 32 (shownin FIGS. 2-3) through which material, such as an unwanted fraction (e.g.plasma), can be withdrawn from the internal chamber 26 to isolate theselected fraction (e.g. red blood cells).

As depicted in FIGS. 1-3, in an example, the skimmer assembly 24 caninclude an access tube 34 that extends through the rotor 22 into theinternal chamber 26. The access tube 34 can define an access channel 36through which material can be withdrawn from or fed into the internalchamber 26. In an example, the access tube 34 can be oriented such thatthe access tube 34 is centered on the rotational axis x-x such that theaccess channel 36 is centered on the rotational axis x-x. The accesschannel 36 can be fluidly connected to the orifice 32 of the buoy 28 byan adjustable connector or tube 37. The adjustable tube 37 can comprisea coil tube or other connector configured to adjustably maintain thefluid connection between the orifice 32 of the buoy 28 and the accesschannel 36 of the access tube 34 as the buoy 28 moves along the buoytrack 30 within the internal chamber 26.

In an example, the skimmer assembly 24 can include a plurality of buoys28, each buoy 28 being moveable along a buoy track 30. In thisconfiguration, the skimmer assembly 24 can include an adapter 38 havinga plurality of connectors 40, wherein an adjustable tube 37 can connecteach connector 40 with an orifice 32 of a corresponding buoy 28 asillustrated in FIGS. 2 and 3. The connected buoys 28 can cooperate towithdraw the selected fraction through their respective orifices 32 andfeed the material into the access channel 36. In an example, each buoytrack 30 can extend radially outward from the rotational axis x-x suchthat the buoys 28 move radially inward and outward from the rotationalaxis x-x. The buoy tracks 30 are oriented evenly around the radial axisx-x to balance the rotor 22 as the rotor 22 is rotated.

As depicted in FIGS. 1-3, in an example, the rotor 22 can include aradial wall 42 extending from a bottom wall 44. The rotor 22 can includea top wall (not shown) integral to the radial wall 42 such that theradial wall 42 extends from the bottom wall 44 to the top wall to definethe internal chamber 26. Alternatively, the rotor 22 can include a topcap 46 engagable to the radial wall 42 to such that the top cap 46 andthe radial wall 42 and the bottom wall 44 cooperate to enclose theinternal chamber 26. In certain examples, the access tube 34 can extendthrough an access port 47 defined by the top cap 46, wherein the rotor22 can include a rotating seal 48 positioned in the access port 47 topermit rotation of the rotor 22 about the access tube 34.

As depicted in FIGS. 1-3, in an example, each buoy track 30 can beoriented radially outward and downward from the access tube 34. In thisconfiguration, the buoy 28 moves radially and downward from the accesstube 34 to rest on the surface of the selected fraction. As such, thelower volume of the selected fraction and/or underlying fractions, thefurther outward and lower the buoy 28 is positioned. The positioning ofthe buoy 28 can improve the stability of the rotor 22 during rotation.

In operation, a multi-component fluid can be received within theinternal chamber 26 of the rotor, where the rotor 22 can be rotatedabout the rotational axis x-x at a first speed to fractionate themulti-component fluid within the internal chamber 26. In operation, therotor 22 can be rotated about the rotational axis x-x at a first speedto fractionate the multi-component fluid within the internal chamber 26.The denser fluid and solid fractions are pushed further outward radiallyfrom the rotational axis x-x by the rotation of the rotor 22 while theless dense fluid fractions remain closer to the rotational axis x-x. Theplurality of fractions can comprise at least one solid fractioncontaining the solid material and at least one liquid fractioncontaining the liquid material. In certain examples, the plurality offractions can comprise multiple liquid fractions having differentdensities.

A brake can be applied to the rotor 22 to stop rotation of the rotor 22or slow rotation of the rotor 22 to a second speed slower than the firstspeed causing the denser fluids and solids to settle toward the bottomwall 44. Lighter fluids of the fractionated components settle above thedenser fractionated components. The buoy 28 can comprise a material ormaterials that provide the buoy 28 with a specific gravity thatcorresponds to a supernatant comprising the denser fractionatedcomponents. In an example, the specific gravity can be less than 1 g/cc.The buoy 28 can float of the surface of the supernatant or between thesupernatant and a fraction floating on the supernatant. As illustratedin FIGS. 2 and 3, the orifice 32 can be positioned on the buoy 28 suchthat a lighter fraction or waste fluid settled on the supernatant can bewithdrawn through the orifice 32 of the buoy 28 floating on thesupernatant.

In an example, red blood cell compatible fluids can be supplied to solidfraction within the internal chamber 26 through the access tube 34 andthe orifice 32 of the buoys 28. The RBC compatible fluids can include,but are not limited to solutions for rejuvenating RBCs within the solidfraction. For example, REJUVESOL red blood cell processing solutionproduced by BIOMET BIOLOGICS of Warsaw, Ind. can be added to the solidfraction. In this configuration, the rotor 22 can be rotated aboutrotational axis x-x at a low agitation speed to intermix or suspend thesolid fraction with the RBC compatible fluids. In an example, the rotor22 can be heated to about ordinary body temperature (37 C) during theagitation period to further improve rejuvenation of the RBCs. Theagitation period can be about 60 minutes.

Wash fluids can be supplied to the internal chamber 26 through theaccess tube 34 and the orifice 32 of the buoys 28. The rotor 22 can becontinuously rotated or pulsed about the rotational axis x-x to suspendor intermix at least the solid fraction with the additional wash fluids.The rotor 22 can then be rotated at the first speed or other high speedto fractionate the wash fluid-solid fraction mixture. Followingfractionation, the brake can be applied to the rotor 22 to stop or slowrotation of the rotor 22 to the second speed or other slow speed tocause the heavier fractions to settle within the internal chamber 26with the lighter fractions and/or wash fluids settling on thesupernatant of the heavier fractions. The buoy 28 can re-settle on thesurface of the supernatant such that the lighter fractions and/or washfluids can be withdrawn through the orifice 32 of the buoy 28. Theprocess can be repeated until the solid fraction is sufficiently washed.In an example, the wash fluids can be added after the red blood cellcompatible fluids are added and the agitation period is completed.

The solid fraction can be withdrawn from the internal chamber 26 throughthe buoy 28 following washing of the solid fraction. To facilitatewithdrawal of the solid fraction, additional wash fluid or diluent canbe fed into the internal chamber 26. The rotor 22 can be rotated orpulsed to intermix the solid fraction with the wash fluid or diluent tosuspend the solid fraction within the fluid. In an example, the rotor 22can be rotated at a third speed slower than the first speed for breakingup the solid fraction and entraining the solid fraction within thefluid. The third speed can be determined to maintain the solid fractionwithin the wash fluid without fractionating the intermixed solidfraction within the additional fluid. The solid fraction entrainedwithin the fluid can then be withdrawn from the internal chamber 26through the orifice 32 of the buoy 28.

VARIOUS NOTES & EXAMPLES

Example 1 is a blood washing system, comprising: a rotor defining aninternal chamber for receiving a multi-component fluid, the rotor beingrotatable about a rotational axis at a first speed to fractionate themulti-component fluid into a plurality of fractions; and a skimmerassembly including at least one buoy moveable along a buoy trackpositioned within the internal chamber, wherein the buoy defines anorifice fluidly connected to an access port in the rotor; wherein thebuoy comprises a specific gravity corresponding to a selected fractionof the plurality of fractions such that the buoy floats on the selectedfraction.

In Example 2, the subject matter of Example 1 optionally includes therotor having a radial wall extending from a bottom wall.

In Example 3, the subject matter of Example 2 optionally includeswherein the rotor further comprises: a top cap engagable to the radialwall to enclose the internal chamber; wherein the top cap defines theaccess port.

In Example 4, the subject matter of any one or more of Examples 1-3optionally include wherein the skimmer assembly further comprises: anaccess tube extending through the access port, the access tube definingan access channel for moving materials into and out of the internalchamber; wherein the orifice of the buoy is fluidly connected to theaccess channel.

In Example 5, the subject matter of Example 4 optionally includeswherein access tube is configured to be coupled to a device forsupplying or withdrawing fluid from the internal chamber of the rotor.

In Example 6, the subject matter of any one or more of Examples 4-5optionally include wherein the access tube is aligned with therotational axis.

In Example 7, the subject matter of any one or more of Examples 4-6optionally include wherein the rotor further comprises: a rotating sealpositioned within the access port to prevent passage of material aroundthe access tube.

In Example 8, the subject matter of any one or more of Examples 4-7optionally include wherein the buoy track extends radially outward fromthe access tube such that the buoy moves radially outward from therotational axis along the buoy track.

In Example 9, the subject matter of Example 8 optionally includeswherein the buoy track is oriented downward such that the buoy movesdownward as the buoy moves radially outward from the rotational axisalong the buoy track.

In Example 10, the subject matter of any one or more of Examples 4-9optionally include wherein the skimmer assembly comprises: a first buoydefining a first orifice and moveable on a first buoy track; and asecond buoy defining a second orifice and moveable on a second buoytrack; wherein the first buoy track and the second buoy track extendradially outward from the rotational axis in opposite directions tobalance the rotor during rotation.

In Example 11, the subject matter of Example 10 optionally includeswherein the skimmer assembly further comprises: an adapter having aplurality of connectors including: a first connector connected to thefirst orifice, and a second connector connected to the second orifice;wherein the adapter is fluidly connected to the access channel toconnect the first and second buoys to the access tube.

In Example 12, the subject matter of any one or more of Examples 1-11optionally include wherein the bottom wall of the rotor includes aslanted surface slanted toward an apex.

In Example 13, the subject matter of any one or more of Examples 1-12optionally include that the specific gravity of the buoy is less than 1g/cc.

Example 14 is a method of washing blood, comprising: providing amulti-component fluid into an internal chamber of a rotor, wherein askimmer assembly including at least one buoy moveable along a buoy trackis positioned within the internal chamber; rotating the rotor at a firstspeed to fractionate the multi-component fluid into a plurality offractions; braking the rotor to reduce the rotation of the rotor to asecond speed slower than the first speed such that the plurality offractions is stacked vertically within the rotor; wherein the buoycomprises a specific gravity corresponding to a selected fraction of theplurality of fractions such that the buoy floats on the selectedfraction.

In Example 15, the subject matter of Example 14 optionally includeswherein the buoy defines an orifice fluidly connected to an access portin the rotor.

In Example 16, the subject matter of Example 15 optionally includeswithdrawing at least one fraction of the plurality of the fractionsfloating above the selected fraction through the orifice in the buoy.

In Example 17, the subject matter of any one or more of Examples 14-16optionally include wherein the selected fraction comprises a supernatantover a solid fraction.

In Example 18, the subject matter of Example 17 optionally includesadding wash fluids to the internal chamber; and rotating the rotor toagitate the solid fraction and intermix the wash fluids with the solidfraction.

In Example 19, the subject matter of Example 18 optionally includesrotating the rotor to fractionate the wash fluid and solid fraction intoa plurality of fractions; braking the rotor to reduce the rotation ofthe rotor to stack the plurality of fractions vertically arranged withinthe rotor; and withdrawing at least one fraction of the plurality of thefractions floating above the supernatant of the selected fractionthrough the orifice in the buoy.

In Example 20, the subject matter of any one or more of Examples 17-19optionally include adding a suspension quantity of wash fluids; rotatingthe rotor to agitate the solid fraction and intermix the wash fluidswith the solid fraction; and withdrawing the intermixed solid and washfluid mixture.

Each of these non-limiting examples can stand on its own, or can becombined in any permutation or combination with any one or more of theother examples.

The above detailed description includes references to the accompanyingdrawings, which form a part of the detailed description. The drawingsshow, by way of illustration, specific embodiments in which the presentsubject matter can be practiced. These embodiments are also referred toherein as “examples.” Such examples can include elements in addition tothose shown or described. However, the present inventors alsocontemplate examples in which only those elements shown or described areprovided. Moreover, the present inventors also contemplate examplesusing any combination or permutation of those elements shown ordescribed (or one or more aspects thereof), either with respect to aparticular example (or one or more aspects thereof), or with respect toother examples (or one or more aspects thereof) shown or describedherein.

In the event of inconsistent usages between this document and anydocuments so incorporated by reference, the usage in this documentcontrols.

In this document, the terms “a” or “an” are used, as is common in patentdocuments, to include one or more than one, independent of any otherinstances or usages of “at least one” or “one or more.” In thisdocument, the term “or” is used to refer to a nonexclusive or, such that“A or B” includes “A but not B,” “B but not A,” and “A and B,” unlessotherwise indicated. In this document, the terms “including” and “inwhich” are used as the plain-English equivalents of the respective terms“comprising” and “wherein.” Also, in the following claims, the terms“including” and “comprising” are open-ended, that is, a system, device,article, composition, formulation, or process that includes elements inaddition to those listed after such a term in a claim are still deemedto fall within the scope of that claim. Moreover, in the followingclaims, the terms “first,” “second,” and “third,” etc. are used merelyas labels, and are not intended to impose numerical requirements ontheir objects.

The above description is intended to be illustrative, and notrestrictive. For example, the above-described examples (or one or moreaspects thereof) may be used in combination with each other. Otherembodiments can be used, such as by one of ordinary skill in the artupon reviewing the above description. The Abstract is provided to complywith 37 C.F.R. § 1.72(b), to allow the reader to quickly ascertain thenature of the technical disclosure. It is submitted with theunderstanding that it will not be used to interpret or limit the scopeor meaning of the claims. Also, in the above Detailed Description,various features may be grouped together to streamline the disclosure.This should not be interpreted as intending that an unclaimed disclosedfeature is essential to any claim. Rather, inventive subject matter maylie in less than all features of a particular disclosed embodiment.Thus, the following claims are hereby incorporated into the DetailedDescription as examples or embodiments, with each claim standing on itsown as a separate embodiment, and it is contemplated that suchembodiments can be combined with each other in various combinations orpermutations. The scope of the present subject matter should bedetermined with reference to the appended claims, along with the fullscope of equivalents to which such claims are entitled.

1. A blood washing system, comprising: a rotor defining an internalchamber for receiving a multi-component fluid, the rotor being rotatableabout a rotational axis at a first speed to fractionate themulti-component fluid into a plurality of fractions; and a skimmerassembly including at least one buoy moveable along a buoy trackpositioned within the internal chamber, wherein the buoy defines anorifice fluidly connected to an access port in the rotor; wherein thebuoy comprises a specific gravity corresponding to a selected fractionof the plurality of fractions such that the buoy floats on the selectedfraction.
 2. The blood washing system of claim 1, the rotor having aradial wall extending from a bottom wall.
 3. The blood washing system ofclaim 2, wherein the rotor further comprises: a top cap engagable to theradial wall to enclose the internal chamber; wherein the top cap definesthe access port.
 4. The blood washing system of claim 1, wherein theskimmer assembly further comprises: an access tube extending through theaccess port, the access tube defining an access channel for movingmaterials into and out of the internal chamber; wherein the orifice ofthe buoy is fluidly connected to the access channel.
 5. The bloodwashing system of claim 4, wherein the access tube is configured to becoupled to a device for supplying or withdrawing fluid from the internalchamber of the rotor.
 6. The blood washing system of claim 4, whereinthe access tube is aligned with the rotational axis.
 7. The bloodwashing system of claim 4, wherein the rotor further comprises: arotating seal positioned within the access port to prevent passage ofmaterial around the access tube.
 8. The blood washing system of claim 4,wherein the buoy track extends radially outward from the access tubesuch that the buoy moves radially outward from the rotational axis alongthe buoy track.
 9. The blood washing system of claim 8, wherein the buoytrack is oriented downward such that the buoy moves downward as the buoymoves radially outward from the rotational axis along the buoy track.10. The blood washing system of claim 4, wherein the skimmer assemblycomprises: a first buoy defining a first orifice and moveable on a firstbuoy track; and a second buoy defining a second orifice and moveable ona second buoy track: wherein the first buoy track and the second buoytrack extend radially outward from the rotational axis in oppositedirections to balance the rotor during rotation.
 11. The blood washingsystem of claim 10, wherein the skimmer assembly further comprises: anadapter having a plurality of connectors including: a first connectorconnected to the first orifice, and a second connector connected to thesecond orifice; wherein the adapter is fluidly connected to the accesschannel to connect the first and second buoys to the access tube. 12.The blood washing system of claim 2, wherein the bottom wall of therotor includes a slanted surface slanted toward an apex.
 13. The bloodwashing system of claim 1, wherein the specific gravity of the buoy isless than 1 g/cc.
 14. A method of washing blood, comprising: providing amulti-component fluid into an internal chamber of a rotor, wherein askimmer assembly including at least one buoy moveable along a buoy trackis positioned within the internal chamber; rotating the rotor at a firstspeed to fractionate the multi-component fluid into a plurality offractions; braking the rotor to reduce the rotation of the rotor to asecond speed slower than the first speed such that the plurality offractions is stacked vertically within the rotor; wherein the buoycomprises a specific gravity corresponding to a selected fraction of theplurality of fractions such that the buoy floats on the selectedfraction.
 15. The method of claim 14, wherein the buoy defines anorifice fluidly connected to an access port in the rotor.
 16. The methodof claim 15, further comprising: withdrawing at least one fraction ofthe plurality of the fractions floating above the selected fractionthrough the orifice in the buoy.
 17. The method of claim 14, wherein theselected fraction comprises a supernatant over a solid fraction.
 18. Themethod of claim 17, further comprising: adding at least one of washfluids and red cell compatible fluids to the internal chamber; androtating the rotor to agitate the solid fraction and intermix the washfluids with the solid fraction.
 19. The method of claim 18, furthercomprising: rotating the rotor to fractionate the wash fluid and solidfraction into a plurality of fractions; braking the rotor to reduce therotation of the rotor to stack the plurality of fractions verticallyarranged within the rotor; and withdrawing at least one fraction of theplurality of the fractions floating above the supernatant of theselected fraction through the orifice in the buoy.
 20. The method ofclaim 17, further comprising: adding a suspension quantity of washfluids; rotating the rotor to agitate the solid fraction and intermixthe wash fluids with the solid fraction; and withdrawing the intermixedsolid and wash fluid mixture.